Bumping gaia.json for 2 gaia-central revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/da99b63fe2f2
Author: Ryan VanderMeulen <rvandermeulen@mozilla.com>
Desc: Merge pull request #14056 from nth10sd/bug939976

Bug 939976 - JavascriptException: TypeError: invalid 'in' operand voice lockscreen.js

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https://hg.mozilla.org/integration/gaia-central/rev/bf978b35e922
Author: Gary Kwong <gary@rumblingedge.com>
Desc: Bug 939976 - JavascriptException: TypeError: invalid 'in' operand voice lockscreen.js, r=vingtetun